So, when and where should you have this chat? Well, it's probably not a good idea to do it at, like, a loud restaurant or something. You want to choose a private place where you both feel comfortable.
And, as for the time - try to pick a moment when you're both relaxed. Like, maybe after a chill weekend or something. You don't want to have this conversation when you're both stressed or anxious - that's just going to make things worse.
It's kind of like planning a surprise party - you want to choose the right time and place to make it special (but, you know, not special in a good way, more like special in a "this is a big deal" kind of way).
How to Break Up with Your Boyfriend - wikiHow